Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Disturbances in the normal redox state of cells can cause toxic effects through the production of peroxides and free radicals that damage all components of the cell.
In humans, oxidative stress is thought to be involved in the development of various disorders and diseases, such as cancer, Parkinson's disease, Alzheimer's disease, atherosclerosis, heart failure, myocardial infarction, fragile X syndrome, Sickle Cell Disease, lichen planus, vitiligo, autism, and chronic fatigue syndrome, certain cardiovascular diseases and ischemia. Oxidative stress also contributes to tissue injury following irradiation and hyperoxia, as well as in diabetes. Oxidative stress is also thought to contribute to the aging process and age related cancer. The reactive species produced in oxidative stress can cause direct damage to the DNA and are therefore mutagenic, and it may also suppress apoptosis and promote proliferation, invasiveness and metastasis. Infection by Helicobacter pylori which increases the production of reactive oxygen and nitrogen species in human stomach is also thought to be important in the development of gastric cancer.
Chemically, oxidative stress is associated with increased production of oxidizing species or a significant decrease in the effectiveness of antioxidant defenses, such as glutathione.
Production of reactive oxygen species (ROS), such as free radicals and peroxides, is a particularly destructive aspect of oxidative stress.
An antioxidant is a molecule that inhibits the oxidation of other molecules. Antioxidants are often reducing agents, such as thiols, ascorbic acid, or polyphenols.
Also some keto compounds, such as 3-hydroxy butyrate have been used. Pharmaceutical compositions of 3-hydroxy butyrate and oligomers thereof suggested for treatment of neurodegenerative disorders, such as Alzheimer's disease, are disclosed in WO 2006020179, US 2009253781 and WO 0004895. These documents also disclose similar compositions for neutriceutical use.
The use of antioxidants in pharmacology is intensively studied, particularly as treatments for stroke and neurodegenerative diseases. According to National Institute of Health report, scientific studies involving more than 100,000 people combined have tested whether antioxidant supplements such as vitamins C and E, selenium, and carotenoids can help prevent chronic diseases. In most instances, antioxidants did not reduce the risks of developing these diseases.
Accordingly, there is still need for developing further antioxidants.